Development of lithium ion secondary batteries having high energy density is moving forward along with recent reduction in size and weight of electric appliances. It is also required to improve battery properties along with expansion of the area where lithium ion secondary batteries are applied.
For example, Patent Literature 1 which aims to provide a lithium secondary battery having excellent battery chemistry properties discloses an electrolyte for lithium secondary batteries containing benzenesulphonyl fluoride or p-toluenesulphonyl fluoride.
Patent Literature 2 which aims to provide a non-aqueous electrolyte secondary battery having high battery properties and being safe even at high temperature discloses a secondary battery including a non-aqueous electrolyte containing a compound reactive with an alcohol such as acetyl chloride or ethanoyl chloride.
Patent Literature 3 and 4 which seek an additive for suppressing gas generation and improving continuous charge characteristics and storage characteristics at high temperature disclose an electrolyte containing, as an additive, methanesulphonyl fluoride or (SO2F)—C3H6—(SO2F).
Patent Literature 5 discloses an electrolyte which aims to improve storage characteristics and cycle characteristics and contains a sulphone compound represented by CH3OCOCF2CF2SO2F and ethylene carbonate and diethyl carbonate as solvents.